PERFORMER NOTES

MasterWorks Gate and other software synths

This month, we recap on using Digital Performer with software synths of all kinds, and take a good look at DP3's built-in MasterWorks Gate plug-in.

Robin Bigwood

Next to all the high-end compressors and reverbs we all rave about, gates can often seem about as glamorous as the average headphone distribution box. But good gates, used well, are powerful and useful tools that can deliver all sorts of interesting effects. If you've got DP3 then you've got a very good one -- MasterWorks Gate.

Consider a very simple gate, such as one you might hang off the end of a row of guitar pedals. The idea is that when you're not playing your guitar, the gate is closed, and all the unwanted noise being pumped out by your stomp boxes is suppressed. The moment you start to play, though, the gate detects a much higher signal level arriving at its input and allows the signal to pass. When you stop playing, the signal level falls and the gate closes again. A gate like this has perhaps only one control -- Threshold Level -- which determines the signal level necessary for it to allow an audio signal through.

MasterWorks Gate behaves in a very similar way. It certainly has a Threshold control, but there are plenty of others too, making it a rather more complex beast. To get a feel for how these work, try putting a mono M

Current Version

* Digital Perfomer: v3.02.

asterWorks Gate on a snare drum track. You should see activity in the level meters to the left of the input/output graph. These represent input level (on the left) and key level (on the right). The two meters are needed because, in common with many other gates and compressors, MasterWorks Gate can be controlled (or 'keyed') by a signal other than the actual audio input -- see the box on the right for more details.

If you set the Key Source to 'Input', the meters should display roughly the same thing as each other. Make sure Key Listen is set to 'Gate', set Range to '-Infinity', Attack and Hold to 0ms and Decay to about 50ms, and what you have is a simple noise gate. If you set the Threshold high (by turning the knob or dragging the red trian

Keying Gates

By default, MasterWorks Gate is controlled (or 'keyed') by the level of the audio in the track it's been placed on. But if you select alternative key sources, the gate can be made to work independently from the audio in the track, offering some excellent creative possibilities.

One possible source is Digital Performer's internal audio busses. Try putting the gate on a track carrying a synth pad or other sustaining sound. Then route the output of, say, a hi-hat track to a buss, and select that same buss in MasterWorks Gate's Key Source pop-up menu. A moment's twiddling should yield a stuttering, staccato version of your original track, and you only need add a stereo version of the Delay plug-in to qualify for your passport to techno heaven.

MasterWorks Gate can also respond to MIDI keying, although you'll need to have Inter-Application MIDI enabled in your FreeMIDI or OMS Setup. Set the Key Source to MIDI Notes, and then switch to the Tracks window. Look in a MIDI track's Output pop-up menu and you'll see the Gate appear as if it were a MIDI instrument. Select it, record some notes in the track (you won't hear them of course, and their pitch is irrelevant) and on playback, the Gate will be triggered by them. As I hinted in last month's Performer Notes, using Step Record is a fine way of entering this type of ultra-rhythmic MIDI key track.

gle) you may never hear anything, but as you lower it, your snare should start to ring through. It might sound shorter than it did when it was recorded, but that's because much of the snare's natural decay falls below the Threshold level and is therefore being chopped off. If you lower the decay further and adjust the threshold so that the snare only just triggers the gate, you'll see what I mean. 'Drum-tightening' duties like this are one of the main uses for gates.

As you might have noticed, the Decay parameter controls how long it takes for the gate to close when the input has fallen below the Threshold level. Long decays preserve the natural envelope of a percussive sound, and short ones cut it off abruptly. In addition to Decay, MasterWorks Gate also has a Hold parameter. This keeps the gate fully open for a specified amount of time after the input level has fallen below the threshold, and at the end of that time the gate gradually closes over the period of time specified with the Decay knob. By setting short Decays and suitable Hold times, it's possible to shape something like a heavily compressed snare drum so that it lasts longer than would normally be possible when using only the Decay setting. To help you set it up, the Hold knob has three lights associated with it. The red one indicates that the gate is closed, green tells you that the gate is fully open, and yellow shows that the input level has fallen below the threshold, but that the gate is in its Hold phase.

MasterWorks Gate has two more main controls: Attack and Range. The Attack control sets the time it takes for the gate to open when an input signal passes the threshold. This may not sound like a big deal, but the parameter can make percussive instruments sound like they have been 'bowed' (if you set a string-like slow attack), or can enable you to remove the click of the drum stick from the beginning of a snare drum. Basically, the longer the attack time, the more sluggish a percussive instrument will sound. Range, meanwhile, sets the amount of attenuation of the input signal whenever it's below the threshold. Simply put, with it set at anything other than '-Infinity' the gate doesn't fully close, so a signal below the threshold will still be audible, if somewhat quieter.

Just as with a good compressor, it takes practice to get the best out of MasterWorks Gate. A good way of learning it is to try some of MOTU's presets and to play a range of sounds through them (adjusting the input level so that it's 'around' the threshold, not constantly above or below it). The status indicators above the Hold knob then give a good idea of what's going on.

ce for a mono Gate, and the stereo version of the plug-in has a 'detector link' facility so that both sides of a stereo gate can be keyed by the summed signal of two separate key inputs.

Software Synths Primer

DP3 is able to integrate with nearly all the major software instruments on the market, but it does so in a number of distinctly different ways. As this often seems to cause so much confusion, especially with those new to DP3, here's a brief guide to the main ways to use plug-in instruments.

* INTER-APPLICATION MIDI

You won't get far using software instruments unless you have 'Inter-Application MIDI' enabled. If you're not sure about this, check out your FreeMIDI Preferences in the FreeMIDI setup application (they're under the File menu), and make sure the Inter-Application MIDI box is ticked.

* VST SYNTHS

If there's a 'standard' for software synths at all, it's VST. By itself, DP3 doesn't support VST plug-ins or synths, but it can with the help of some third-party MAS plug-ins that act as a 'shell' or environment in which the VST synth runs. The most useful of these is Audio Ease's VST Wrapper v3, which costs a mere $49.95 to download from www.audioease.com. However, the weird and wonderful Pluggo from www.cycling74.com can also run VST plug-ins, and if you're serious about software synths it's worth getting Pluggo alongside VST Wrapper. Both of these come with very good documentation dealing with the installation and use of VST synths.

Using a VST plug-in synth inside DP3 is quite straightforward. Working with VST Wrapper v3, for example, you go to the Mixing Board and select your software synth by clicking and holding on an audio track's insert slot (I'd always recommend using an Aux track for this). Then choose the synth you want from the VST Wrapper submenu that appears listing all your other MAS plug-ins. Finally, go to the Tracks window and select the synth in a MIDI track's Output pop-up menu, and record-enable the MIDI track. If you want to record the synth's output to another audio track, set the input to a buss or buss pair in an unused audio voice track. Choose this same buss or bu

Quick Tips

There's a monster DP3/VST plug-in compatibility chart at www.oxygenhose.com together with lots of other DP3 goodies.

Remember that many VST and MAS software synths use a lot of memory, particularly those using sample playback of some sort. Don't be surprised if you need to allocate over 150MB of RAM to DP3 on a system with plenty of synths and plug-ins.

ss pair for the output of your synth track, then record-enable the new track. Now you can bounce down your synth to audio, which is especially helpful when you're running short of processor power.

* STAND-ALONE SYNTHS

Many software synths and samplers run as 'stand-alone' applications on your Mac, so they don't require a VST shell. Examples are Unity by Bitheadz and nearly everything by Native Instruments. Synths like these work with DP by letting it know when they're running, and DP, in response, adds them to its list of MIDI destinations (Outputs). For maximum flexibility, though, a stand-alone synth also needs to be able to route its audio directly into DP, and this is normally done via a 'MAS Input' plug-in that gets written to your Mac's Plug-ins folder (inside the MOTU folder in your Mac's Extensions folder) when you install the synth. With this little file in place, the synth should show up in the list of possible audio inputs inside DP. Just as with a VST synth, you have to dedicate an Aux track to handling the synth's audio. You'll almost certainly have to make sure that the stand-alone synth is configured to output audio via MAS, and that it's not responding directly to your master keyboard.

* MAS SYNTHS

More and more synths are becoming available in MAS format, which means that they run inside the DP3 environment without further ado or need for a VST shell. In virtually all respects, using a MAS synth is the same as using VST Wrapper to run one in VST format.

* THE SMALL PRINT

Latency is definitely an issue when using software synths with DP3. If you use SoundManager for audio, there's not a lot you can do to improve matters, but if you're using MOTU hardware, you can always change the Samples per Buffer value. Basically, at higher settings (which, of course, result in lower load on your Mac's processor), output from software synths is likely to sound late, and that's why many users bounce the outputs of software synths to conventional audio tracks as early as possible in the recording process. At least that way you can put a mix together with virtual and hardware MIDI synchronised. With any luck, MOTU might build latency compensation into DP3 before too much longer.

If everything is set up correctly, but you're still not hearing any sound, it's worth checking the settings in the Input Monitoring Mode dialogue box (found under the Configure Audio System option in the Basics menu). And you'll definitely need 'Play in Background' turned on in your Preferences file if you want to duck outside of a playing DP3 sequence to tweak a stand-alone synth.

For more on using synth plug-ins with DP, plus info on OMS and Rewire, look up my previous Performer Notes columns from SOS May 2001 (see www.soundonsound.com/sos/ may01/articles/performernotes.asp) and SOS June 2001 -- see www.soundonsound.com/sos/ jun01/articles/performernotes.htm.

New MAS Plug-ins

There has been a veritable deluge of MAS-based instrument plug-ins in the last few months. Joining IK Multimedia's Sampletank are Spectrasonics' Atmosphere, Trilogy and Stylus, all high-quality sample-based plug-ins. Seen at the NAMM show, MAS versions of the Tassman modelling synth and Lounge Lizard electric piano emulator by Applied Acoustics Systems are due for imminent release. And finally, the long awaited Plugsound instruments seem to have become part of the UVI (Universal Virtual Instrument) by Big Fish Audio, and should be available soon. Visit www.spectrasonics.com, www.applied-acoustics.com and www.plugsound.com for more details and demo versions.